Esters of an oxyalkylated phenol-formaldehyde resin as a lubricating oil detergent



3,096,285 Patented July 1963 group is an alkylene oxy radical of 2 toabout 4 carbon 3,096,286 atoms. ESTERS OF AN OXYALKYLATED PHENOL-FORM-ALDEHYDE RESIN As A LUBRICATENG OIL It can be seen that R taken with itsattached carbon DETERGENT atom is part of an acyl radical of about 6 to24, preferably Joseph A. Verdoi, Dalton, Ill., assignor, by mesneassignabout 12 t carbon atomsments, to Sinclair Research Inc., New York,N.Y., a In general, the dispersant of the invention which isusecorporation of Delaware ful in maintaining sludge and varnishformations sus- NO m Fllfid Jail- 11, 1,425 pended in the oil isprepared by reacting, in the designated 3 Clalms- 252-57) ratios, ofabout 1 mole of an alkylated phenol, preferably p-alkylated, in whichthe alkyl group contains from about 4 to 15 carbon atoms, about 0.5 to 2moles of formaldehyde or its polymers which yield formaldehyde; about 1This invention relates to oleaginous base lubricants having improveddispersant properties. More particularly, it relates to lubricantscontaining certain organic esters that is, a small amount of the estersof the condensation :S g 25 2 2 2? g 3 2 32 2; g g gigi g fig product ofa phenol-formaldehyde resin with an alkylene p b y t 0 7 t 1 5 f f thde. a on i o mo es 0 a atty ac1 or its ester, e

As is weu known in the art straight or uncompounded residue (the carbonchain attached directly to the carboxyl mineral oils are often deficientin one or more respects giggggfigfffi i 1 2:; 12 :58; ig z if 535 2 5 gsgisg g z ggfiggs fg f s g g g g sgfif ester of the alkyleneoxide-phenol-forma ldehyde condensa. densation product of aphenol-formaldehyde resin with g product'f In fg reactaon prqcedure[cl-1e an alkylene oxide when added to a lubricating oil prop pg g 'ormaare hreacte 1 o gwe a vides a lubricant that has improvedcharacteristics for g i gg fifg g ii g; z g g ff g dispersing solidmaterials appearing in the oil during use p S b1 h d h f H and thusreduces deposition of such materials on engine .ulta e p eno 1creactants me u at e o pamparts. Chemical compounds which are known fortheir temarybutylphenoi; Para secondarybutylphenol; pamfunction ofenabling a lubricating oil medium to maintain P f pam'lsooctylphenol para'nony1pheI.101; paraoxidation products, resins and other types ofinsoluble decylphenol paia'dqdecylphenoh the correspondmg ortho materialin suspension or dispersion in the oil are lubricatp f 1S and g i m $3 gi 'gi g p ing on detergent additives. p astic, oxya y ation susceptl e,p eno -a e y e resins,

I have found that an ester of the condensation product which can be usedmtiarmedlaties to Produce the prodof a phenol-formaldehyde resin withalkylene oxide in nets of the i :lilventlon partlfmlarly from P qlubricating oil is effective in solubilizing or dispersing in hyde anddltiunctlolizil phenol phenol m which the oil solids of the type thatare normally formed during one the reactlvs posmons 6) has beenSubstituted by a hydrocarbon group and particularly by one having at usein an internal combustion engine. The oil-soluble esters of thecondensation product of a phenol-formaldeleast 4 carbon atoms and morethan 15 Carbon atoms, hyde resin with an alkylene oxide usable in thelubricants 1S well-known and usually lnchlfie temperatures of about ofthis invention are believed to be exemplified by the t0 at afimospheflcreduced elevated following formula: pressures.

RI! 0 RI! 0 0 OH ([311 o) i'1-R' 0(OH (IJHO) i' -R' ll P n 2-O(OHq-OHO)DCR' H r J; C I I H H R R m R wherein: The alkylene oxideswhich may be used to react with p the phenol-aldehyde resin are thealpha-beta oxides havnzabout 1 to preferably about 2 to ing not morethan 4 carbon atoms, i.e. ethylene oxide,

m=about 0 to 10, preferably at least 1; R=an alkyl group, includingcycloalkyl, straight or i li' g i ig g i p g 95 8 branched chain havingabout 4 to 15 carbon atoms; g 01 an i y g O avmg 9 21.1116 Sm a e R,:analkyl group including cycloalkyl, straight or resln of the kinddescribed, such resln 1s sub ected to branched chain having about 5 to23 carbon atoms treatment with a reactive olefin i .oifiyalkylatwnpreferably about 11 to of the resins of the kind from which theinitialreactants n hyd n or lower of up to ab 2 Carbon sed in the practice ofthe present lnventlon are prepared atoms the is advantageously catalyzedby the presence of an alkali.

OH OH 0) Useful alkaline catalysts include soaps, sodium acetate,

2 sodium hydroxide, sodium methylate, caustic potash, etc.

The amount of alkaline catalyst usually is between 0.2%

3 to 2%. The temperature employed may vary from room temperature to ashigh as about 200 C. or more. The reaction may be conducted with orwithout pressure, i.e. from zero pressure to approximately 200 or even300 p.s.i.g. or more. In general, the method employed is substantiallythe same procedure as used for oxyalkylation of other organic materialshaving reactive phenolic groups. It is advantageous to conduct theoxyalkylation in the presence of an inert solvent such as xylene,cymene, Decalin, ethylene glycol diethylether, diethylene glycol,diethylether, or the like, although with many resins, the oxyalkylationproceeds satisfactorily without a solvent. This is particularly true inthe manufacture of products from low-stage resins, i.e. up to about 7units per molecule.

Suitable fatty monocarboxylic acids for use in this invention have atleast about 6 carbon atoms, and the preferred group of fatty acids haveabout 12 to 20 carbon atoms. The fatty acids include caprylic,pelargonic, capric, undecylic, lauric, myristic, palmitic, stearic andarachidic. Mixtures of fatty acids having at least 6 carbon atomsobtained from the saponification of fats and fatty oils for example maybe employed. Naphthenic acids and hydrofol acids (hydrogenated fish oilfatty acids) are also suitable fatty acids. When the fatty acid has lessthan about 8 carbon atoms the ester tends to have less solubility inlubricating oils. The solubility of the ester increases as the length ofthe fatty acid chain increases. Accordingly, the fatty acid preferablyhas at least about 12 carbon atoms.

The esters of the reaction product of the condensation of aphenol-aldehyde resin with an alkylene oxide are useful asdeposit-control additives in lubricants. The oil base of lubricatingviscosity in which the additives may be used to form superior lubricantsincludes mineral oils, synthetic lubricating oils and mixtures thereof.The hydrocarbon lubricating oils usable in this invention can beparaflin base, naphthenic base or mixed parafiin-naphthene basedistillate or residual mineral or petroleum oils. Paraffin basedistillate lubricating oil fractions can be used in the formulation ofpremium grade motor oils. The lubricating base generally is subjected tosolvent refining to improve its lubricity and viscosity temperaturerelationship as well as solvent dewaxing to remove waxy components andimprove the pour of the oil. Preferably, lubricating oils having an SUSviscosity at 100 F. between about 50 and 1000 may be used in theformulation of the improved lubricants of this invention and often theviscosity range falls between about 70 and 300 at 100 F.

Among the synthetic lubricating bases useful in this invention are theester or ether type. High molecular weight, high boiling, liquidaliphatic dicarboxylic acid esters possess excellentviscosity-temperature relationships and lubricating properties and arefinding ever-increasing utilization in lube oils adapted for high andlow temperature lubrication; esters of this type are used in theformulation of jet engine oils. Examples of this class of syntheticlubricating bases are the diesters of acids such as sebacic, adipic,azelaic, alkenyl succinic, etc; specific examples of these diesters aredi-Z-ethylhexyl sebacate, di-2- ethylhexyl azelate, di-Z-ethylhexyladipate, di-n-amyl sebacate, di-Z-ethylhexyl-Z-dodecyl suocinate,di-Z-ethoxyethyl sebacate, di-2'-methoxy-2-ethoxyethyl sebacate (themethylcarbitol diester), di-2-ethyl-2-n-butoxyethyl sebacate (theZ-ethylbutyl Cellosolve diester), di-Z-n-butoxyethyl azelate (then-butyl Cellosolve diester) and di-2-'- n-butoxy-2-ethoxyethyl-n-octylsuccinate (the n-butyl Carbitol diester).

Polyester lubricants formed by a reaction of an aliphatic dicarboxylicacid, a glycol and a monofunctional aliphatic monohydroxy alcohol or analiphatic monocarboxylic acid in specified mole ratios are also employedas the synthetic lubricating base in the compositions of this invention.Polyesters formed by reaction of a mixture containing specified amountsof dipropylene i glycol, sebacic acid and 2-ethyl-hexanol and a mixturecontaining adipic acid, diethylene glycol and 2-ethylhexanoic acidillustrate the class of synthetic polyester lubricating bases.

Polyalkylene ethers as illustrated by polyglycols are also used as thelubricating base in the compositions of this invention. Polyethyleneglycol, polypropylene glycol, polybutylene glycols and mixedpolyethylene-polypropylene glycols are examples of this class ofsynthetic lubricating bases.

The sulfur analogs of the above-described diesters, polyesters andpolyalkylene ethers are also used in the formulation of the lubricatingcompositions of this invention. Dithioesters are exemplified bydi-Z-ethylhexyl thiosebacate and di-n-octylthioadipate; polyethylenethioglycol is an example of the sulfur analogs of the polyallryleneglycols; sulfur analogs of polyesters are exempliiied by the reactionproduct of adipic acid, thioglycol and Z-ethylhexyl mercaptan.

The lubricating oils usually contain other additives designed to impartother desirable properties to it; for example, V.I. improvers such asthe polymethacrylates; wear inhibitors, pour point depressants,corrosion inhibitors and oxidation inhibitors which will function incombination with the esters of this invention.

The ester additives of the present invention can be prepared as shown inthe following example.

Into a reaction vessel equipped with a thermometer, reflux condenser,and stirrer was placed 2 moles of t-octyl phenol and grams (1.67 moles)of formalin. The reaction was catalyzed by the addition of 0.6 gram ofconcentrated sulfuric acid dissolved in 20 ml. of water. The mixture washeated under reflux for one hour and the calculated amount of calciumoxide was added to neutralize the sulfuric acid present. The flask wasthen converted to a distillation system and the mixture was dehydratedin vacuo (30 mm.) to a pot temperature of C. The product was cooled to100 C. and poured into a stainless steel beaker, where it solidified toa colorless, transparent resin.

One hundred and eighty grams of the above resin was placed in anautoclave with 0.5 gram of powdered KOH. Two hundred and forty-eightgrams of propylene oxide was added to the mixture and the autoclave wassealed. The mixture was heated to 300 F. and a pressure of p.s.i.g. Inone hour the pressure dropped to 0.0 p.s.i.g. and the autoclave wasopened. A very viscous, almost colorless, polymer was obtained which didnot behave as a dispersant (according to carbon black suspension tests).

Two hundred and six grams of the above propylene oxide condensationproduct was placed in a flask containing-119.4 grams of methyl stearateand 3.25 grams of tetraisopropyl titanate. The mixture was heated at 200C. under a stream of nitrogen until a total of 9 grams of methyl alcoholwas collected. The reaction mixture was then heated under vacuum at 200C. for 15 hours. The resulting product was a straw-colored, mobileliquid which was completely soluble in mineral lubricating oil. A onepercent blend of this additive in the mineral lubricating oil showed thefollowing properties:

K.V. at 100 K.V. at 130 18.50 K.V. at 210 5.56 Pour F 5 V1 99.5

Carbon Black Suspension Test 6 After several weeks the carbon blackstill remained in polymer consisting essentially of an ester of an oxyalkylsuspension. When the test was made on a blank lube oilatedphenol-formaldehyde resin wherein said oil-soluble kerosene mixturecontaining none of the polyester addipolymer has the formula:

RI! 0 RN 0 I ll 1 H R" 0 0(OH?CH-O)n-O-R' 0(OH2- H-O),,OR 4 1:1

O(OH2 Ho).. R H t C 3 a H t 1 t R R mR tive, the carbon black remainedin suspension for only wherein: n=about l to m=about 0 to 10; R =alkyl afew hours. group, of about 4 to carbon atoms; R=alkyl group The esteradditives of this invention are added to the of about 11 to 19 carbonatoms, and R is selected from lubricating oils in amounts sufiicient toimpart solidthe group consisting of hydrogen and an alkyl radical ofdispersant properties to the oils and usually are about 20 1 to 2 carbonatoms. 0.1 to 10% of the oil, preferably about 0.5 to 2%. Thus, 2. Thelubricant composition of claim 1 wherein the as specific examples, 1% ofthe additive of the above ester additive is present in the mineral oilin an amount example can be added to a solvent refined Mid-Continent ofabout 0.5 to 2% of the oil. lube oil of 100 SUS at 100 F. viscosity orto di-Z-ethyl- 3. The composition of claim 1 wherein R" is methyl.hexylsebacate synthetic oil.

I l i References Cited in the file of this patent I. An oleaginouslubricant composition consisting es- UNITED STATES PATENTS sentially ofa mineral oil of lubricating viscosity and about 0.1 to 10% of the oilto maintain in suspension sludge 2,499,360 De Groom et a1 Mal 1950 andvarnish formed during use :of said lubricant composi- 2,499,363 DeGroote et a1 Mar. 7, 1950 tion in an internal combustion engine of anoil-soluble 2,499,364 De Groote et al Mar. 7, 1950

1. AN OLEAGINOUS LUBRICANT COMPOSITION CONSISTING ESSENTIALLY OF AMINERAL OIL OF LUBRICATING VISCOSITY AND ABOUT 0.1 TO 10% OF THE OIL TOMAINTAIN IN SUSPENSION SLUDGE AND VARNISH FORMED DURING USE OFSAIDLUBRICANT COMPOSITION IN AN INTERNAL COMBUSTION ENGINE OF ANOIL-SOLUBLE POLYMER CONSISTING ESSENTIALLY OF AN ESTER OF ANOXYALKYLATED PHENOL-FORMALDEHYDE RESIN WHEREIN SAID OIL-SOLUBLE POLYMERHAS THE FORMULA: